I've always wished I could do this. I can tell you that you don't miss much, just the ability to freak a few girls out. I sort of have this ability, except more so in a verbal sense that I remember every conversation I have had with any girl I like. It does tend to freak them out a little, like "I told you that?!" "Yes, multiple times." When you can turn around and say "At 2.05 on the 23rd of June you were staring at me, wearing a light blue dress, before I was forced to move other and stand next to you and your grandma who stated, 'What's with the waiting?." We were then ushered in to the lecture theater where you proceeded to laugh at the professors name, exclaim excitement at the prospect of a field trip, ask whether I was alone, that I should get some information pack and then upon leaving ask for my number where we stood awkwardly outside the theater before I left to go to the station." Some girls run for the hills and others just stare at you like a mad man. (I can do this sort of stuff for every girl from the age of 8 onward.) That is incredibly awesome. Looking like a weirdo is probably a drawback, but I'd still like to have that ability.